Why even bring her from the drydock inside the spacedock?
I'd argue that Spacedock Earth is exclusively for embarkation and disembarkation - the equivalent of a commercial airport, only in orbit. Perhaps it's even a civilian installation for the most part, with Starfleet just holding a pier or two (at least during the militant 2280s). That the Excelsior
is there is a sign that all work on her has been brought to completion and she's ready to embark on test flights.
As for "surprise", I don't see much of that in the eyes of the heroes. Awe, perhaps - but the Excelsior
isn't a surprise, merely the shiny new thing, now presented to their eyes for the first time.
As much as I enjoyed the refit-E's aesthetic, that was something I had issue with.
OTOH, a "refit" usually is an ugly thing, built of compromise atop compromise...
We could similarly dismiss the comparable Constellation
ugliness as old technology taken to ridiculous extremes before new tech steps in. But the Miranda
and the Sydney
are ugly the very same way, with protruding this-and-that, and they supposedly aren't refits or extreme experiments.